Method of vulcanizing caoutchouc and the product derived therefrom



Patenteddlune 10,. 1930 UNITE STATES.

PATENT. OFFICER" 1.03m 13. sm'annn, or AKRON, 01:10, ASSIGNOR '10 THE eoonxmn mm & RUBBER comrm, or AKRON, 1:10, A conroaa'rron or onro Y I METHOD 0] 'VULCANIZING CAOUTGHOUG AND THE PRODUCT DERIVED THEBEFB/OH 89 Drawing. Original My invention relates to'the treatment of rubber and it has for its primary object the provision of a desirable material for acceleratilpig the vulcanization of rubber products.

. ore specifically my invention has for one of its objects the provision of an accelerator which is composed of the reaction products of a mercaptothiazole and an aldehyde amine condensation product.

This .application is a division of application( Serial No. 219,365, filed September 13, 192

It has preiiiously been known that mercaptothiazolesi, were powerful accelerators of.

the "vulcanization of rubber products. It

i has also been known that the mercaptothiacondensation product's,

zoles might be caused to react with other sub- The radicals indicated by the characters R and R may be either straight chain or cyclic hydrocarbons.

This class of compounds includes the reaction products of crotonaldehyde and aniline, (crotylidene aniline), acetaldehyde and aniline (ethylidene aniline), crotonaldehyde methylamine, propyl aldehyde and ethylamine, butyl aldehyde,aniline, butyl aldehyde 'heptalde-.

toluidine, heptaldehyde aniline, hyde butyl amine, aniline cinnamic aldehyde,

and numerous other hydrocarbon compounds which include thez'grouping indicated in the formula.

' A specific example of a compound which falls within the scope of my invention is the crotonaldehyde aniline mercaptobenzothiaapplication flied September. 18, 1927, Serial 1T0. 219,865. Divided and this application flied June 12, 1928. Serial No. 284,888. a

zole reaction prepared as ollows:

roduct. This material may be 7 Intermix molecular quantities of the mer- I captobenzothiazole and the crotonaldehyde aniline reaction products, and reflux them for a. period of two hours or more. An exothermic reaction takes place during this period. Also, water and hydrogen sulphide are given off, as is evident from the odor and the appearance of the condensate. The

product obtained is a thick semi-solid which may be hardened to a resin-like state by distilling ofi a little aniline. The chemical formula of the reaction product is unknown.'. It is to be understood that this method of preparing the reaction product of the mencaptothiazole and the Schifi bases is of general application, and may be employed to manufacture various other materials of this class, which have beenmentioned'. I

The material prepared according to the above described method may be incorporated into various rubber compounds. The following is a sampleformula of a compoundwhich insures excellent results:

Pale crepe rubber 100 parts Zinc oxide 5 parts Sulfur 3 parts Stearic acid 1.5 parts Accelerator The accelerative properties of the material prepared according to the method discussed were tested in the above formula and the results obtained are tabulated 'in the following tables.

TABLE I Mercwptobenzothicaole control a Cure 2 22 Tensile Percent i rats: ta-k line 11 .milm Pressure kgs/cm 8 Pounds m 20 13 as 117 940 40 22 .72 156 s40 60 20 24 4 111 825 20 as 102 180 800 .5 part Team I I" Mercaptobenzothiazole solid ethylidene aniline Cure 500 g Tensile Per cent 53: fg itre/ngtl; elgug. 12?. Time in gs cm rea mim Pressure kgs/cm kgslcm I P undo 16 20 19 78 145 860 30 20 30 110 165 775 40 20 34 132 200 780 20 38 147 210 770 90 20 40 155 205 755 120 20 41 160 210 750 Tables I and II respectively contain data obtained by testing samples in which the pure mercaptobenzothiazole and crotyhdene aniline were used as accelerators. Table III contains data obtained from tests conducted upon samples containing the reactlon product of mercaptobenzothiazole and the croton- .aldehyde aniline condensation product. Ta-

ble IV contains data obtained from the testing of rubber samples containing the reaction products of mercaptobenzothiazole and ethylidene aniline. Comparison of the data contained in Tables I and II with that contained in Tables III and IV clearly indicates that the reaction products of the mercaptothiazoles and the Schifi bases are materially more powerful accelerators than either mercaptothiazole or crotylidene aniline alone.

Since the product resulting from the combination of the thiazole and the Schiiis base is a more powerful accelerator than either of the original compounds, it is evident that a true chemical reaction takes place. The latter fact may be further demonstrated by extracting the final product with an alkali.

The latter treatment would remove any unreacted mercaptobenzothiazole in itsprginal state. Since no free mercaptobenzothiazole 18 thus obtained, it is clear that it has combined with the Schifis base.

Althou h I have disclosed only the referred em odiments of my invention an described those embodiments in detail, it will be apparent to those skilled in the art that the invention is not so limited, but that various minor modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What I claim is:

1. A method of treating rubber which comprises heating a vulcanizable rubber compound containing a reaction product of a mercaptothiazole with ethylidene aniline.

2. A method of treating rubber which'comprises heating a vulcanizable rubber compound containing a reaction product of mercaptobenzothiazole with ethylidene aniline.

3. A method of treating rubber which comprises vulcanizin it in the presence of a reaction product 0 a mercaptothiazole with a reaction product of an aromatic amine and an aliphatic aldehyde. 7

4. A rubber product that has been vulcanized in the presence of a reaction product of a mercaptothiazole with ethylidene aniline.

. 5. A rubber product that has been Vulcan-- ized in the presence of a reaction product of a mercaptothiazole with a condensation product of an aromatic amino with an aliphatic aldehyde.

6. A rubber product that has been vulcanized in the presence of a reaction product of a mercaptobenzothiazole with ethylidene aniline. 4

7. A method of. treating rubber which comprises subjecting it to vulcanization in the presence of a reaction product of a mercaptobenzothiazole and a derivative of an amino lslubistituted benzene and an aliphatic alde- 8. A method of treating rubber which comprises subjecting it to vulcanization in the presence of a reaction product of a mercaptobenzothiazole and a derivative of a primary amine containing a single benzene nucleus and an aliphatic aldehyde.

-9. A method of treating rubber which comprises subjecting it to vulcanization in the presence of a reaction product of mercaptobenzothiazole and a derivative of a material selected from a group comprising aniline and toluidine and an aliphatic aldehyde selected from a group comprising acetaldehyde, croton aldehyde, butyl aldehyde and heptaldehyde.

10. A method of treating rubber which comprises subjecting it to vulcanization inv the presence of a reaction product of mercaptobenzothiazole and a derivative of a primary aromatic amine containing a single benzene' nucleus and an aliphatic aldehyde.

11. A rubber product that has been vulv canized in the presence of a reaction product of mercaptobenzothiazole and ethylidene aniline.

L In witness whereof, I have hereunto signed my name.

S1gned at Akron, in the connty of Summit, and State of Ohio, this llth day of June,

LORIN B; SEBRELL. 

